air pump question

Post by **misha** » 03 Apr 2009, 18:26

What are the symptoms when air pump(with all of the following components) doesn't work,when fails?

Could it be possible that if air pump fails,car is running rich?

Post by **Ozark Lee** » 03 Apr 2009, 18:55

When any component in the SAS (air pump) fails the ECU disables the fuel trim which would lead to a richer than normal mixture.

...Lee

Post by **misha** » 03 Apr 2009, 19:26

Richer than normal?Meaning...black smoke from the exhaust all of the time or just when engine is cold,untill engine reach working temperature?
Btw...what is fuel trim?
Thanks for fast answers Lee!

Post by **Ozark Lee** » 03 Apr 2009, 19:51

Fuel trim is the duty cycle of the injectors - how long they pulse each time they fire. VADIS just says that the fuel trim is disabled and doesn't elaborate on how long it is disabled. From other SAS problem posts it seems to be all the time once the error is detected.

*Disclaimer*

Thank God, none of my cars have a SAS system so I have no hands on knowledge.

From the way VADIS describes it the car might have black smoke at idle that would get better as the cars speed increases.

We had another post in the last couple of days where the fuel mileage decreased by about 25% with a bad air pump so black smoke would be reasonable in that condition.

...Lee

Post by **misha** » 04 Apr 2009, 09:39

That explains why my car is running rich everytime i disconnect battery(i wrote about that about a month or so).
My air pump doesn't work for about 5-6 years.Car is adapted right now-no black smoke and no running rich.
I guess i was wrongly informed about air pump functionality by my Volvo dealer who said to me that air pump's only purpose is to reduce emissions in exhaust when engine is cold,and that air pump is working just for a few minutes untill engine warms up.After engine warms up at operating temperature air pump is no longer active and can't affect to air-fuel mixture.

The only time that car should running rich,when air pump is not working,is when engine is cold.When warms up it should dissapear.
But according to what you said, it affects all the time!

Thanks...Lee!

Post by **jblackburn** » 04 Apr 2009, 13:33

The only time that car should running rich,when air pump is not working,is when engine is cold.When warms up it should dissapear.
But according to what you said, it affects all the time!

The air pump technically only is supposed to run when the car is cold, until it reaches operating temperature. However, I had mine go bad, and during extended periods of idling (specifically in very cold weather) it would try to turn on, and fail, and trip the check engine light. The air pump ITSELF does not affect the fuel trim, but instead just the check engine light being on for any condition will disable this. I noticed about a 3-5 mpg loss of mileage, but no black smoke from my car in the 3 months before I got around to replacing it. As long as you keep resetting the check engine light (Auto zone/Advance will do it for free), you won't have to worry about this, but ultimately I had to replace mine for the car to pass inspection.

Post by **misha** » 04 Apr 2009, 16:54

I live in Serbia,so i don't have emission test controls like you guys in u.s.
You said that you don't have black smoke from exhaust,but i have.When i reset light or when disconnect battery for a while it's all ok for a day or two and after that black smoke comes again.Everything is normal except high fuel consumption and black smoke.Car runs normaly,idles normaly,drives normaly and the ONLY thing that indicates that something is wrong is,as i said before,black smoke from the exhaust and high fuel consumption.
I don't have that problem anymore

,it looks like engine is adapted to run without air pump since it runs for 5-6 years without,but i have check engine on and i'm affraid to disconnect battery again.
Thanks guys!

Post by **misha** » 05 Apr 2009, 08:40

Is there anybody else who can tell me what are the symptoms when air pump fails,like black smoke from the exhaust?

Post by **MadeInJapan** » 05 Apr 2009, 11:24

A little rich mixture but usually not enough for black smoke- and of course those trouble codes- this pump only comes on for a short time at start-up and sometimes if you're sitting at a red light.

Post by **misha** » 05 Apr 2009, 17:14

So,nobody of you guys didn't have black smoke as a result of failed air pump.Hmmm....interesting.Why am i the only one whose car have the worst symptoms when something fails???

Can i do something to fool ecu that air pump is there and working and to get rid of the pump with all of her's components?I read one post about how to do something with wires on front o2 sensor,maf and rear o2.Is it safe?Has anyone actually repeat that procedure and succeed?